November 12, 2021 Library of Congress Celebrates GIS Day Focused on the 2020 Census

This year’s GIS Day at the Library of Congress, an event held annually during Geography Awareness Week, will focus on the 2020 Census, which provides a snapshot of American demographics like no other geospatial sources available. Geography is a cornerstone of the census and geographic information systems help map and analyze the spatial distribution of people, goods, programs and services. 

GIS offers real-world applications for demographic analysis as well as for planning and management of natural resources, transportation, housing, and myriad social services. Geography enthusiasts, teachers, students and professionals celebrate GIS Day across the globe with community events to highlight the benefits of geospatial science in addressing the world’s challenges.

This year’s GIS Day at the Library will be virtual on Nov.17, with invited speakers who will explore the role that geographic information sciences played in the 2020 Census in assembling the data that tells the evolving story of the country. They will also discuss how geographers, cartographers and policy makers use census results to analyze social and economic trends.

Mandated by the U.S. Constitution since 1790, decennial census results determine the number of seats in Congress, mapping of electoral districts, and disbursement of billions of dollars in federal funds for new roads, schools, hospitals, housing and other public sector services. GIS mapping plays a key role in all stages of the census process.

GIS Day 2021 at the Library of Congress: Mapping the 2020 Census

Keynote: Deirdre Bishop, chief of the Geography Division at the U.S. Census Bureau, will discuss how the agency leans on a complex address database to monitor massive amounts of population data. She will also explain the use of computing technology to match data with satellite imagery and will provide an overview of the predictive agent-based models used in the Census Bureau’s Response Outreach Area Mapper, a tool to better identify and analyze hard-to-survey areas.

Three technical papers will focus on historic census data, the application of the census to congressional redistricting and the controversy over the new method of private data protection used by the Census Bureau in 2020. 

Other presenters will discuss archiving methods and data accuracy and protection:

• David Van Riper, director of Spatial Analysis at the Institute for Social Research and Data Innovation at the University of Minnesota, will speak about archiving Census data and the work of the National Historical Geographic Information System.
• Richard Leadbeater, director of State Government Solutions for the GIS software company, Esri, will explain how GIS is affecting the use of census results in congressional redistricting. 
• John Hessler, a specialist in Geographic Information Science at the Library of Congress and a lecturer at Johns Hopkins University, will introduce participants to the mathematics of Database Reconstruction Theoremsand the influence of differential privacy algorithms, like TopDown, on the accuracy of the 2020 Census data for geographical and policy analysis.

The program will premiere on Nov.17 at 1 p.m. EST on both the Library’s YouTube page and website. Presentations will also be available for viewing at a later day.

The Library of Congress is the world’s largest library, offering access to the creative record of the United States — and extensive materials from around the world — both on-site and online. It is the main research arm of the U.S. Congress and the home of the U.S. Copyright Office. Explore collections, reference services and other programs and plan a visit at loc.gov; access the official site for U.S. federal legislative information at congress.gov; and register creative works of authorship at copyright.gov.